46 research outputs found
Quasi-exactly solvable quartic: elementary integrals and asymptotics
We study elementary eigenfunctions y=p exp(h) of operators L(y)=y"+Py, where
p, h and P are polynomials in one variable. For the case when h is an odd cubic
polynomial, we found an interesting identity which is used to describe the
spectral locus. We also establish some asymptotic properties of the QES
spectral locus.Comment: 20 pages, 1 figure. Added Introduction and several references,
corrected misprint
Universality of Cluster Dynamics
We have studied the kinetics of cluster formation for dynamical systems of
dimensions up to interacting through elastic collisions or coalescence.
These systems could serve as possible models for gas kinetics, polymerization
and self-assembly. In the case of elastic collisions, we found that the cluster
size probability distribution undergoes a phase transition at a critical time
which can be predicted from the average time between collisions. This enables
forecasting of rare events based on limited statistical sampling of the
collision dynamics over short time windows. The analysis was extended to
L-normed spaces () to allow for some amount of
interpenetration or volume exclusion. The results for the elastic collisions
are consistent with previously published low-dimensional results in that a
power law is observed for the empirical cluster size distribution at the
critical time. We found that the same power law also exists for all dimensions
, 2D L norms, and even for coalescing collisions in 2D. This
broad universality in behavior may be indicative of a more fundamental process
governing the growth of clusters
Approaching criticality via the zero dissipation limit in the abelian avalanche model
The discrete height abelian sandpile model was introduced by Bak, Tang &
Wiesenfeld and Dhar as an example for the concept of self-organized
criticality. When the model is modified to allow grains to disappear on each
toppling, it is called bulk-dissipative. We provide a detailed study of a
continuous height version of the abelian sandpile model, called the abelian
avalanche model, which allows an arbitrarily small amount of dissipation to
take place on every toppling. We prove that for non-zero dissipation, the
infinite volume limit of the stationary measure of the abelian avalanche model
exists and can be obtained via a weighted spanning tree measure. We show that
in the whole non-zero dissipation regime, the model is not critical, i.e.,
spatial covariances of local observables decay exponentially. We then study the
zero dissipation limit and prove that the self-organized critical model is
recovered, both for the stationary measure and for the dynamics. We obtain
rigorous bounds on toppling probabilities and introduce an exponent describing
their scaling at criticality. We rigorously establish the mean-field value of
this exponent for .Comment: 46 pages, substantially revised 4th version, title has been changed.
The main new material is Section 6 on toppling probabilities and the toppling
probability exponen
Influence of Milling Time During the Mechanical Alloying Process on the Properties of Fe-3Si-0.75P Alloy
The lithosphere of the Earth as a nonlinear system with implications for earthquake prediction
Colliding cascades model for earthquake prediction
1.1 The model We explore here the process wherein seismicity undergoes a qualitative change, culminating in a major earthquake. This is done for synthetic seismicity generated by the model of collidin
Formal morphostructural zoning of mountain territories
Formalization of morphostructural zoning of mountain regions, with special emphasis on determination of lineaments, is considered in this paper. The zoning is based on joint analysis of topography, geology, tectonics and geomorphology, represented on corresponding maps and aerial or space photos. Our goal is to make the zoning objective and reproducible. The importance of this goal follows from the fact that morphostructural zoning, especially the scheme of lineaments, is the starting point of our approach to prediction of strong earthquakes; it is important also to location of some mineral deposits. The definition of large elements of relief is formalized in the first place. On the basis of their characteristics a territory is divided into three types of areas: blocks, lineaments and knots. A precise and objective location of knot and lineament positions is the final aim of our formalized scheme. The application of the suggested algorithm to Eastern Tien Shan is described in the conclusion of the paper, as an illustration.
ARK: https://n2t.net/ark:/88439/y085028
Permalink: https://geophysicsjournal.com/article/158